Processing of adenovirus 2-induced proteins.

Area of Science:

• Molecular Virology
• Protein Biochemistry

Background:

• Adenovirus 2 infection induces the synthesis of numerous viral polypeptides in host cells.
• Understanding the precise synthesis pathways and maturation of viral proteins is crucial for comprehending the viral life cycle.

Purpose of the Study:

• To identify and characterize adenovirus 2-induced polypeptide components.
• To investigate potential precursor-product relationships among these viral proteins.

Main Methods:

• Analysis of (35)S-methionine-labeled cell extracts from adenovirus 2-infected KB cells.
• Short-term labeling and chase experiments in nonradioactive medium.
• Peptide mapping of methionine-containing tryptic peptides.

Main Results:

• Identified 22 virus-induced polypeptide components.
• Observed delayed appearance of radioactivity in two virion components during chase experiments, correlating with a decrease in nonvirion proteins, suggesting precursor-product relationships.
• Demonstrated shared methionine-containing tryptic peptides between a precursor candidate (P-VII) and mature virion protein VII, with P-VII possessing an additional methionine residue.

Conclusions:

• At least two adenovirus 2 virion components are derived from the post-translational cleavage of higher molecular weight precursor polypeptides.
• This cleavage mechanism is a key step in the maturation of adenovirus 2 structural proteins.